Implement SSL decryption

This is a very lightweight SSL decryption capability for ChopShop. It requires the private key and only supports a small number of cipher suites (but can be extended). It requires M2Crypto for the heavy lifting.

I've also implemented module chaining so you can do things like:

./chopshop -f tests/ssl/ssl3.pcap "chop_ssl -k tests/ssl/server.key -v | payloads -t -u"
./chopshop -s . -f tests/ssl/ssl3.pcap "chop_ssl -k tests/ssl/server.key -v | http | http_extractor -s"